The present invention relates to anti-inflammatory activity of eggshell membrane, processed eggshell membrane preparations and eggshell membrane isolates and combinations thereof.
Eggshell membrane is composed of two individual membranes between egg albumin and eggshell. The membranes are primarily comprised of protein fibers. The fibers appear to be a network or scaffold predominantly containing Type I collagen fibers that are encapsulated in a continuous mantle of proteoglycans and other macromolecules. (see T-M, et. al., Matrix Biology, 14:507-513, 1994). The thickness of the two membranes ranges from 73-114 μm in eggs from White Leghorn and New England pullets. (see “Egg Science and Technology” Eds. W. J. Stadelman and O. J. Cotterill, Food Products Press, a subsidiary of The Haworth Press, Bingham, N.Y., 1990) The outer membrane has a thickness ranging from 53.2 μm to 65.5 μm in White Leghorn eggs while the inner membrane ranges form 19.5 μm to 24.3 μm.
Britton and Hale reported that the proteins of shell membranes exhibited a high content of arginine, glutamic acid, methionine, histidine, cystine, and proline. (see Britton, W. M. and hale, K. K., Poultry Science, 56:865-871, 1977) Baker and Balch and Harris, et. al. found that eggshell membranes also contained hydroxyproline, hydroxylysine, and desmosine. (see Baker, J. R. and Balch, D. A., Biochem. J., 82: 352-361, 1962; see also Harris, E. D., Blount, J. E. and Leach, R. M., Science, 200: 55-56, 1980) Subsequent studies by Wong et. al. demonstrated the presence of Type I and Type V collagen in eggshell membrane. (see Wong, M, et. al., Dev. Biology, 104:28-36, 1984) Arias, et. al. subsequently identified the presence of Type X in eggshell membrane and postulated that Type X collagen functions to inhibit mineralization and establishes a zone protected from mineral deposition. (see Arias, J. L., et. al., Connective Tissue Research, 26: 37-45, 1991; Aria, J. L., et. al., Matrix, 11: 313-320, 1991; see also Arias, J. L., et. al., Connective Tissue Research, 36: 21-33, 1997)
Eggshell membrane also has been shown to contain acid glycosaminoglycans including dermatan sulfate and chondroitin-4-sulfate. Picard, et. al., isolated and characterized sulfated glycoproteins from eggshell membrane. (see Picard, J., Paul-Gardais, A., and Vedel, M, Biochimica et Biophysica Acta, 320: 427-441) Glycoproteins included hexosamines, hexoses, and fucose. More recently, significant amounts of hyaluronic acid have been detected in eggshell membrane (U.S. Pat. No. 6,946,551.). Other components identified in eggshell membrane include ovotransferrin, desmosine and isodesmosine, lysyl oxidase, and lysozyme. (see Gautron, J., et. al., Connective Tissue Research, 42:255-267, 2001; Starcher, B. C. and King, G. S., Connective Tissue Research, 8:53-55, 1980; and Akagawa, M, et. al., Biochim. Biophys. Acta, 14:151-160, 1999; Hincke, M. T., et. al. Matrix Biology, 19:443453, 2000)
Eggshell membranes are examples of collagenous structures that support development. The most evident function of the membrane is to act as a supporting structure for the egg prior to deposition of a calcified shell and to provide an organic matrix for the deposition of calcium in eggshell formation. The membrane might also be inductive to the developing embryo via secretion of growth factors. The proposed inductive characteristics of eggshell membrane along with its high protein content and significant quantities of glucosamine, chondroitin sulfate, and hyaluronic acid support its potential utility in therapeutics and nutraceuticals.
Compositions, isolates, and proteins from other natural sources have been previously described for therapeutic, cosmetic, and nutraceutical applications. For example, processed antler powder has been suggested for use in nutraceutical compositions containing such powder. The powder is placed in nutraceutical capsules, formed into tablets or used as an ingredient in nutritional bars or beverages. Methods of preparing lipid fractions from sea cucumbers that can be used as nutraceutical supplements to ameliorate immune responses have also been suggested. The isolates are identified as being useful in the treatment of allergic diseases, inflammatory diseases, and hyperproliferative skin diseases. The preparations may be administered orally or formulated into a topical lotion. Others have disclosed the preparation of milk protein hydrolysates and applications for use in cosmetic formulations. The hydrolysates are described as having skin hydrating properties and wound healing characteristics.
Additional examples of materials derived from natural sources, that have been suggested as therapeutic ingredients, include a protein hydrolysate prepared from poultry feet and processed into a powder or gel for use treating burns or for regrowing muscle, skin, and nerve tissues; a method for treating diseased or injured abraded, lacerated, or ulcerated tissue by applying a composition containing sucrose, gelatin, and water; a method and agent for treating inflammatory disorders of the gastrointestinal tract by administering D-glucosamine hydrochloride in solid or liquid form; and compositions containing amino sugars, such as glucosamine, and a glycosaminoglycan, such as chondroitin, to protect, treat and repair connective tissue.
Other oral and topical compositions derived from natural sources for protection, treatment, and repair of connective and skin tissues have been disclosed. For example, an oral and injectable composition comprised of glucosamine, chondroitin sulfate, hydrolyzed or native collagen, sodium hyaluronate, chelated manganese ascorbate, and L-malic acid. The composition acts as a chondroprotective agent, enhances chondrocyte synthesis, healing wounds, and maintaining healthy tissue. Compositions containing glucosamine, chondroitin sulfate, and optionally manganese ascorbate have also been suggested. The topical application or injection of 40-55 wt. % chondroitin sulfate to protect joint cells, reduce aseptic inflammation, and preserve human and animal cells in vitro has also been described. Topical preparations for improving wound healing have also been suggested which include a suspension of collagen and a glycosaminoglycan.
Although certain components (that have now been identified to be present in significant quantities in eggshell membrane, i.e., collagen, glucosamine, chondroitin sulfate, and hyaluronic acid), have been disclosed as being useful in therapeutic and nutraceutical applications, the potential anti-inflammatory activity of processed eggshell membrane and/or eggshell membrane isolates in accordance with the present invention have not been previously described.
Inflammation, as defined in Dorland's Medical Dictionary, is “a localized protective response, elicited by injury or destruction of tissues, which serves to destroy, dilute or wall off both the injurious agent and the injured tissue.” It is characterized by fenestration of the microvasculature, leakage of the elements of blood into the interstitial spaces, and migration of leukocytes into the inflamed tissue. On a macroscopic level, this is usually accompanied by the familiar clinical signs of erythema, edema, hyperalgesia (tenderness), and pain.
The inflammatory response is any response characterized by inflammation as defined above. It is well known, to those skilled in the medical arts, that the inflammatory response causes much of the physical discomfort (i.e., pain and loss of function) that has come to be associated with different diseases and injuries.
A number of mediators of inflammation also act as mediators of pain. Dray and LaBars discuss several cytokines released from immune cells that are able to induce hyperalgesia. (see Dray, A. Inflammatory Mediators in Pain. Brit. J. Anaesthesia. 75:125-131; see also LeBars, D and Adam, F., Nociceptors and Mediators in Acute Inflammatory Pain. 2002. Ann. Fr. Anesth. Reanim. 4:315-335) These cytokines include IL-10, IL-6, IL-8 and TNFα. Hyperalgesia is mediated indirectly via several mechanisms including prostanoid release, increasing nerve growth factor (NGF) or braydkinin receptors or affecting sympathetic fibres.
Cytokines are regulators of host responses to infection, immune responses, inflammation and trauma. Some cytokines make disease worse (pro-inflammatory) and some reduce inflammation and promote wound healing (anti-inflammatory).
Pro-inflammatory cytokines include IL-1α, IL-1β, IL-11, IL-12, IL-17, IL-18, TNFα, monocyte chemoattractant protein (MCP-1, MCP-3, MCP-5), RANTES (RANTES is an acronym for Regulated on Activation, Normal T Expressed and Secreted; It is also known as CCL5), and Macrophage Inflammatory Protein (MIP-1β, MIP-2, MIP-3β). (see Haringham, J J, Ludikhuize, J. and Tak, P P. Chemokines in Joint Disease: the Key to Inflammation? 2005. Ann. Rheum. Dis. 63:1186-1194; Dinarello, C A. Proinflammatory Cytokines. 2000. Chest 118:503-508; Martel-Pelletier, J, Alaaeddine, N, and Pelletier, J-P, Cytokines and Their Role in the Pathophysiology of Osteoarthritis, 1999. Frontiers in Bioscience, 4: 694-703; Stancyk, J., Marekl, L K, Grzegorczyk, J, Szkudlinksa, B, Jarzebska, M, Marciniak, M, and Snyder, M. RANTES and Chemotactic Activity in Synovial Fluids from Patients with Rheumatoid Arthritis and Osteoarthritis. Mediators of Inflammation, 6:343-348; and Bless, N M, Huber-Lang, M, Guo, R-F, Warner, R L, Schmal, H, Czermak, B H J, Shanley, T P, Crouch, L D, Lentsch, A B, Sarma, V, Mulligan, M S, Friedl, H P, and Ward, P A, Role of CC Chemokines (Macrophage Inflammatory Protein-1β, Monocyte Chemoattractant Protein-a, RANTES) in Acute Lung Injury in Rats. J. Immunology, Vol. 164:2650-2659)
Anti-inflammatory cytokines include IL-6, IL-10, IL-12, and IL-13.
Treatments for Inflammation include a variety of anti-inflammatory agents (COX enzyme inhibitors), slow acting, disease-modifying agents, including nutraceuticals such as glucosamine and chondroitin sulfate (Millis) and a number of herbal medicines, including Articulin-F, Avocado, Capsaicin, Devils' Claw, Ginger, Phytodolor, Reumalex, Stinging nettle, and Willow bark (reviewed by Long, et. al.) (see Millis, DL. New Treatments for Osteoarthritis. www.vet.utk.edu; see also Long, L., Soeken, K, and Ernst, E. 2001. Herbal medicines for the treatment of osteoarthritis: a systematic review, Rheumatology 40:779-793.)
U.S. Pat. No. 6,706,267 to Adalsteinsson, et. al., discloses a composition and method for the treatment and prevention of inflammation and inflammatory related disorders. The composition is glucosamine in combination with an egg product. It is generally preferred that the egg product is obtained from an avian which has been hyperimmunized with an immungenic mixture and/or which contains an anti-inflammatory composition. The whole egg comprises an anti-inflammatory composition. The invention is also directed to a method for reducing inflammation in a subject, the method comprising administering to the subject an effective amount of glucosamine and an egg product. While the patent defines “egg product” as any whole egg (table, hyperimmunized or otherwise) or any product or fraction derived therefrom, the invention does not disclose the potential anti-inflammatory activity of the eggshell membrane, hydrolysates or isolates of eggshell membrane and combinations thereof.
Thus, it has not been previously reported to use processed eggshell membrane and/or eggshell membrane isolates as nutraceuticals to protect, treat, and repair of connective tissues, or to reduce joint pain and inflammation related to osteoarthritis, rheumatoid arthritis or other joint disorders.
Further, it has not been previously reported that processed eggshell membrane and/or eggshell membrane isolates exhibit anti-inflammatory properties based on reduction of pro-inflammatory plasma cytokine levels in animals consuming processed eggshell membrane and/or eggshell membrane isolates.
Therefore, processed eggshell membrane and/or eggshell membrane isolates provide a natural composition for potential application in reducing inflammation and pain associated with arthritis and other diseases and disorders exhibiting inflammation and/or pain.